General protection fault

When i run my program, i get the following:

"Exiting due to signal SIGSEGV
General Protection Fault at eip=0001cdc0
eax=00000009 ebx=000ca110 ecx=000ca110 edx=00000000 esi=0000160e
edi=00000009 ebp=000c99f8 esp=000c99e0 program=C:\TEST.EXE
cs: sel=01a7 base=029d0000 limit=000dffff
ds: sel=01af base=029d0000 limit=000dffff
es: sel=01af base=029d0000 limit=000dffff
fs: sel=017f base=00006ca0 limit=0000ffff
gs: sel=01bf base=00000000 limit=0010ffff
ss: sel=01af base=029d0000 limit=000dffff
App stack: [000c9aac..00049aac] Excetn stack: [00049a00..00047ac0]

Call frame traceback EIPs:
0x0001cdc0
0x0001c46e
0x00001757
0x00005548
"

here is the code i have compiled

#include<stdio.h>
struct pattern
{
  char type_of_constraint[50];
  char relation[500];
  char relation_attribute[50];
  char subject[50];
  char subject_with[50];
  char subject_to[50];
  char subject_of[50];
  char subject_in[50];
  char subject_for[50];
  char object[50];
  char object_with[50];
  char object_to[50];
  char object_of[50];
  char object_in[50];
  char object_for[50];
}a;
FILE *fp1,*fp2;
main(int argc,char *argv[])
{
  void Set_must_constraints(char*,char*,char*);
  char str[100],b[10][40];
  int i,j,k,count,t;
  fp1=fopen(argv[1],"r");
  if(fp1==NULL)
  {
    printf("%s : File not found\n",argv[1]);
    return 1;
  }
   fp2=fopen("pattern.dat","wb");
   if(fp2==NULL)
  {
    printf("%s : File not found\n","pattern.dat");
    return 1;
  }
  t=LoadFile(fp1,str);
  while(t==1)
  {
    for(i=j=k=0;str[i];++i)
    {
      if( (str[i]!=' ' && str[i+1]==' ') || (str[i]!='\t' &&
str[i+1]=='\t') ||
          (str[i]!='\n' && str[i+1]=='\n') )
      {
        b[j][k]=str[i];
        ++k;
        ++i;
        b[j][k]='\0';
        k=0;
        ++j;
      }
      else
         {
           b[j][k]=str[i];
           ++k;
         }
    }
    b[j][k]='\0';
    
    if( strcmp("must",b[2])==0 && strcmp("have",b[3])==1 )
    {
      
      if( strcmp("functions",b[1])==0 && strcmp("single_exit",b[4])==0
)
      {
        strcpy(a.type_of_constraint,"Dataflow");
        Set_must_constraints(b[3],b[1],b[4]);
      }
    }
     

    t=LoadFile(fp1,str);
  }
  fclose(fp1);
  fclose(fp2);
  return 0;
}

int LoadFile(FILE *fp,char x[])
{
  int s;
  for(s=0,x[s]=getc(fp);feof(fp)!=1;++s,x[s]=getc(fp))
  {
    if(x[s]=='\n')
    {
      x[s]='\0';
      return 1;
    }
  }
  return 0;
}
     
/* All X must have Y 
   1. All CLASSES must have DEFAULT_CONSTRUCTOR
   2. All CONDITIONAL_EXPRESSIONS must have EXPLICIT_COMPARISON
   3. All IF_STATEMENTS must have ELSE
   4. All FUNCTIONS must have EXPLICIT_RETURN_TYPE
   5. All FUNCTIONS must have SINGLE_EXIT
*/

void Set_must_constraints(char *rel,char *s_in,char *obj)
{
  strcpy(a.relation,rel);
  strcpy(a.relation_attribute,"-1");
  strcpy(a.subject,s_in);
  strcpy(a.subject_with,"-1");
  strcpy(a.subject_to,"-1");
  strcpy(a.subject_of,"-1");
  strcpy(a.subject_in,"-1");
  strcpy(a.subject_for,"-1");
  strcpy(a.object,obj);
  strcpy(a.object_with,"-1");
  strcpy(a.object_to,"-1");
  strcpy(a.object_of,"-1");
  strcpy(a.object_in,"-1");
  strcpy(a.object_for,"-1");
  fprintf(fp2,"%s %s %s %s %s %s %s %s %s %s %s %s %s %s
%s\n",a.type_of_constraint,a.relation,a.relation_attribute,a.subject,a.subject_with,a.subject_to,a.subject_of,a.subject_in,a.subject_for,a.object,a.object_with,a.object_to,a.object_of,a.object_in,a.object_for);
}